Light emitting device and image display unit

ABSTRACT

A light emitting device includes a package having a recess, a lead frame buried in the package so that one end of the lead frame is exposed at a bottom of the recess and another end protrudes to an exterior of the package, a light emitting element arranged on the lead frame exposed at the bottom of the recess, and an encapsulant filled in the recess. The package includes, at the side face where the lead frame protrudes, a first side face formed inwardly relative to a side face of the lead frame, and a second side face formed at a lower portion of the first side face and protruded so as to cover a top face of the lead frame.

CROSS REFERENCE TO RELATED APPLICATION

The application claims the foreign priority benefit under Title 35,United States Code, Section 119(a)-(d) of Japanese Patent ApplicationNo. 2010-177193 filed on Aug. 6, 2010, and Japanese Patent ApplicationNo. 2011-123635 filed on Jun. 1, 2011, the content of which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a surface-mount type light emittingdevice and an image display unit using the same.

2. Description of the Related Art

Lamp type LEDs are often used as light emitting devices that configurerespective pixels of an image display device (a display) placed in anoutdoor location. However, from the standpoint of downsizing, thinning,or heat dissipation, surface-mount type (SMD type) LEDs are graduallybecoming popular.

Following technologies are proposed as such a surface-mount type lightemitting device. For example, JP H10-261821 A (see FIG. 9B) discloses alight emitting device that includes a resin stem and a protrusive partwhich covers the whole upper surface of the resin stem and the wholeupper side surface with a light transmissive thermosetting resin,thereby improving the moisture resistance and the light emittingefficiency. Also, JP 2006-049442 A (see FIG. 1) discloses a lightemitting device that has a heat dissipation member provided on the rearsurface of a lead frame via a conductive layer including a metal,thereby improving the heat dissipation characteristic. Also, JP2006-093738 A (see FIGS. 4 and 10) discloses a light emitting devicethat has a first recess which is formed in the stem and where asemiconductor element is mounted and a second recess formed around thefirst recess in order to make the amount of encapsulation materialencapsulating the semiconductor element always constant.

When the light emitting devices disclosed in JP H10-261821 A, JP2006-049442 A, and JP 2006-093738 A are used as pixels of an imagedisplay device placed in an outdoor location, for example, as shown inFIG. 11A, in order to prevent moisture due to rain water, humidity,etc., from entering into the interior of a light emitting device 101, aside (a surrounding area) of the light emitting device 101, inparticular, a boundary between a package 110 and a lead frame 120 wheremoisture is likely to enter is covered by a waterproof resin 102 formedof a silicon resin or the like.

However, the surface-mount type light emitting devices are small inheight in comparison with the lamp type light emitting devices, so thatthe amount of waterproof resin that can be used is little by whatcorresponds to such smallness. Hence, according to the conventionallight emitting device 101, as shown in FIG. 11B, when it is used for along period, the waterproof resin 102 repeats expansion and shrinkagedue to heat by sunlight or the like, and the waterproof resin and thepackage resin are deteriorated by moisture and ultraviolet, and thus thewaterproof resin 102 may be peeled from the package 110.

As shown in FIG. 11B, when such peeling of the waterproof resin 102reaches the lead frame 120, moisture enters to a light emitting element130 inside the light emitting device 101 from the boundary between thepackage 110 and the lead frame 120, and the light emitting element 130becomes unable to emit light.

The present invention has been made in view of such a problem, and it isan object of the present invention to provide a surface-mount type lightemitting device and an image display unit which suppress peeling of awaterproof resin to a boundary between a package and a lead frame wheremoisture is likely to enter in order to prevent the moisture like rainwater from entering therein even if the waterproof resin covering a sideof the light emitting device starts peeling and which are excellent inwaterproofing.

SUMMARY OF THE INVENTION

In order to achieve the above object, a first aspect of the presentinvention provides a surface-mount type light emitting device thatincludes: a package having a recess formed in an upper face thereof; apair of lead frames buried in the package so that respective one ends ofthe pair of lead frames are exposed at a bottom of the recess andrespective another ends of the pair of lead frames protrude to anexterior from a side face of the package; a light emitting elementarranged on the upper face of at least either one of the pair of leadframes exposed at the bottom of the recess; and an encapsulant filled inthe recess, in which the package includes, at the side face where thepair of lead frames protrudes: a first side face formed inwardlyrelative to a frame side face of the pair of lead frames; and a secondside face formed at a lower portion of the first side face and protrudedso as to cover a top face of the pair of lead frames.

When such a light emitting device employing the above-explainedstructure is used in an outdoor location and the side face thereof iscovered by the waterproof resin, even if the waterproof resin startspeeling due to a long-term use, the waterproof resin can be preventedfrom being peeled to a boundary between the package and the lead framewhere moisture is likely to enter by the step formed between the firstside face formed inwardly relative to the frame side face of the leadframe and the second side face protruding so as to cover respectiveupper faces of the pair of lead frames, and thus entering of moisturelike rain water can be suppressed. When the light emitting device isused in not only an outdoor location but also an indoor location, thepackage side face of the light emitting device may be covered by thewaterproof resin in order to enhance the waterproof performance, and inthis case, the same effect can be obtained.

It is preferable that the pair of lead frames protruding to the exteriorfrom the side face of the package should be bent along the side face ofthe package and a bottom face thereof, the first side face should beformed inwardly relative to the frame side face of the pair of bent leadframes, and the second side face should protrude so as to cover an upperpart of a bent portion of the pair of lead frames.

According to the light emitting device employing such a structure, sincethe second side face protrudes so as to cover the upper part of the bentportion of the pair of lead frames, entering of moisture like rain waterinto the interior of the light emitting device can be furthereffectively prevented.

It is preferable that the package should further include a groove thatis formed between the first side face and the second side face in athickness direction of the package at a predetermined depth.

According to the light emitting device employing such a structure, whenit is used in an outdoor location and the side face thereof is coveredby the waterproof resin, even if the waterproof resin may possibly startpeeling due to a long-term use, the groove formed between the first sideface and the second side face can prevent the waterproof resin frombeing peeled from the package. Also, even if the waterproof resin ispeeled from the side face, the light emitting device can preventmoisture like rain water from entering therein by the groove.

It is preferable that the package should further includes, on a sideface of the package which is closer to a light-emitting-surface of thelight emitting device than the first side face, a third side face formedinwardly relative to the first side face.

According to the light emitting device employing such a structure, whenit is used in an outdoor location and the side face thereof is coveredby the waterproof resin, even if the waterproof resin starts peeling dueto a long-term use, the step formed between the first side face and thesecond side face can prevent the waterproof resin from being peeled fromthe package, thereby preventing moisture like rain water from enteringin the light emitting device. Also, when the light emitting device isused in an outdoor location and the side face thereof is covered by thewaterproof resin, the waterproof resin can be applied with reference tothe third side face.

It is preferable that a height of the first side face in the thicknessdirection of the package should be larger than a height of the secondside face in the thickness direction of the package.

According to the light emitting device employing such a structure, whenit is used in an outdoor location and the side face thereof is coveredby the waterproof resin, the area of the first side face that is areference for application of the waterproof resin can be taken largerthan the area of the second side face, and the waterproof resin can beapplied so that the end of the waterproof resin is located within aplane of the first side face.

In order to achieve the above object, a second aspect of the presentinvention provides an image display unit that includes: a circuit boardincluding the plurality of light emitting devices explained above; and awaterproof resin that is formed so as to cover a side face of thepackage and the frame side face of each of the plurality of lightemitting devices on the circuit board.

According to the image display unit employing such a structure, sincethe side face of the package and the side face of the frame are coveredby the waterproof resin, it is possible to prevent moisture like rainwater from entering in the light emitting device.

It is preferable that the image display unit of the present inventionshould further include a frame member which is formed with a pluralityof openings, and which is joined with the circuit board, the pluralityof light emitting devices being arranged in the plurality of openings.

Since the image display unit employing such a structure includes theframe member, the circuit board and the waterproof resin on the circuitboard can be protected.

It is preferable that the waterproof resin should be formed so as tocover the frame side face and the second side face and a part of thefirst side face.

According to the image display unit employing such a structure, sincethe waterproof resin is formed up to a location within a plane of thefirst side face of the package, it is possible to surly prevent moisturelike rain water from entering in the light emitting device.

In order to achieve the above-object, a third aspect of the presentinvention provides an image display unit that includes: a light emittingdevice; a circuit board including the plurality of light emittingdevices; and a waterproof resin formed on the circuit board, in whichthe light emitting device is a surface-mount type light emitting deviceand includes: a package having a recess formed in an upper face thereof;a pair of lead frames buried in the package so that respective one endsof the pair of lead frames are exposed at a bottom of the recess andrespective another ends of the pair of lead frames protrude to anexterior from a side face of the package; a light emitting elementarranged on the upper face of at least either one of the pair of leadframes exposed at the bottom of the recess; and an encapsulant filled inthe recess, the waterproof resin is formed on the circuit board so as tocover a side face of the package and a side face of the frame of each ofthe plurality of light emitting devices, and the package includes, atthe side face where the pair of lead frames protrudes: a first side faceformed inwardly relative to a frame side face of the pair of leadframes; and a second side face formed at a lower portion of the firstside face and protruded beyond the first side face.

Since the image display unit employing such a structure includes thewaterproof resin covering the side face of the package and the side faceof the frame, it is possible to prevent moisture like rain water fromentering in the light emitting device. Also, even if the waterproofresin starts peeling due to a long-term use, the waterproof resin can beprevented from being peeled to a boundary between the package and thelead frame where moisture is likely to enter by the step formed betweenthe first side face formed inwardly relative to the frame side face ofthe lead frame and the second side face protruding beyond the first sideface, and thus the image display unit can prevent moisture like rainwater from entering therein.

It is preferable that the pair of lead frames protruding to the exteriorfrom the side face of the package should be bent along the side face ofthe package and a bottom face thereof, the first side face should beformed inwardly relative to the frame side face of the pair of bent leadframes, and the second side face should protrude so as to cover an upperpart of a bent portion of the pair of lead frames.

According to the image display unit employing such a structure, sincethe second side face protrudes so as to cover the upper part of the bentportion of the pair of lead frames, it is possible to furthereffectively prevent moisture like rain water from entering in the lightemitting device.

It is preferable that the waterproof resin should be formed so as tocover the frame side face and the second side face and a part of thefirst side face.

According to the image display unit employing such a structure, sincethe waterproof resin is formed up to a location within a plane of thefirst side face of the package, it is possible to further surely preventmoisture like rain water from entering in the light emitting device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are cross-sectional views taken along A-A line of FIG. 3and showing a structure of a light emitting device according to a firstembodiment of the present invention, and FIG. 1A is a diagram showing astate in which no waterproof resin is peeled and FIG. 1B is a diagramshowing a state in which the waterproof resin is partially peeled;

FIG. 2 is a perspective view showing a whole structure of the lightemitting device according to the first embodiment of the presentinvention;

FIG. 3 is a plan view showing a whole structure of the light emittingdevice according to the first embodiment of the present invention;

FIGS. 4A and 4B are schematic diagrams showing an image display unitusing the light emitting device according to the first embodiment of thepresent invention, and FIG. 4A is a perspective view showing a wholestructure of the image display unit, and FIG. 4B is an explodedperspective view showing a whole structure of the image display unit;

FIGS. 5A and 5B are schematic diagrams showing an illustrative imagedisplay device using the light emitting device according to the firstembodiment of the present invention, and FIG. 5A is a diagram showing animage display device, and FIG. 5B is a diagram showing the image displayunit configuring the image display device and the light emitting deviceconfiguring the image display unit;

FIGS. 6A to 6C are schematic diagrams showing manufacturing processes ofthe image display unit using the light emitting device according to thefirst embodiment of the present invention, and FIG. 6A is a diagramshowing a process of arranging a light emitting device, FIG. 6B is adiagram showing a process of applying a waterproof resin, and FIG. 6C isa diagram showing a process of attaching a frame member;

FIGS. 7A and 7B are cross-sectional views showing a structure of a lightemitting device according to a second embodiment of the presentinvention, and FIG. 7A is a diagram showing a state in which nowaterproof resin is peeled and FIG. 7B is a diagram showing a state inwhich the waterproof resin is partially peeled;

FIGS. 8A and 8B are cross-sectional views showing a structure of a lightemitting device according to a third embodiment of the presentinvention, and FIG. 8A is a diagram showing a state in which nowaterproof resin is peeled and FIG. 8B is a diagram showing a state inwhich the waterproof resin is partially peeled;

FIGS. 9A and 9B are cross-sectional views showing a structure of a lightemitting device according to a fourth embodiment of the presentinvention, and FIG. 9A is a diagram showing a state in which nowaterproof resin is peeled and FIG. 9B is a diagram showing a state inwhich the waterproof resin is partially peeled;

FIG. 10 is a cross-sectional view showing a structure of a lightemitting device according to a fifth embodiment of the presentinvention;

FIGS. 11A and 11B are cross-sectional views showing a structure of alight emitting device of the related art, and FIG. 11A is a diagramshowing a state in which no waterproof resin is peeled and FIG. 11B is adiagram showing a state in which the waterproof resin is partiallypeeled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An explanation will be given of a light emitting device and an imagedisplay unit according to embodiments of the present invention withreference to the accompanying drawings. The dimensions (an area, athickness, etc.) of members shown in respective drawings and thepositional relationship thereof and the like are exaggerated in somecases in order to clarify the explanation. In the following explanation,the same name and reference numeral basically denote the same or similarmember, and the duplicated detailed explanation will be omittedaccordingly.

<First Embodiment>

A detailed explanation will be given of a light emitting device 1 of afirst embodiment with reference to FIGS. 1A to 3 and FIGS. 5A and 5B. Inorder to facilitate understanding through the explanation, in FIG. 3, anencapsulation member 40 is illustrated in a transparent manner.

A light emitting device 1 is a surface-mount type used for an imagedisplay device (a display) mainly placed in an outdoor location. In thespecification, as shown in FIGS. 1A and 1B, the surface-mount type (SMDtype) light emitting device has lead frames 20 exposed in a recess 11 ofa package 10 and has light emitting elements 30 on respective leadframes 20 in a surface-mount manner.

As shown in, for example, FIGS. 5A and 5B, the light emitting device 1is used as each pixel configuring an image display device D. When it isviewed through a cross-sectional view, as shown in FIGS. 1A and 1B, thelight emitting device 1 includes the package 10, a pair of lead frames20, the light emitting element 30, the encapsulation member 40, andwires 50. In the following explanation, in order to explain therelationship between the light emitting device 1 and the waterproofresin 2, as shown in FIGS. 1A and 1B, the explanation will be given witha waterproof resin 2 covering a side of the light emitting device 1being illustrated. Also, the waterproof resin 2 is formed so as to coverthe surrounding of the light emitting device 1, but in FIGS. 1A, 1B andother drawings, in order to facilitate understanding through theexplanation, only one side of the light emitting device 1 is covered bythe waterproof resin 2.

<Package>

The package 10 is a member for arranging electronic components like thelight emitting element 30. As shown in FIGS. 1A and 1B, the recess 11with a predetermined depth is formed on the upper surface of the package10. The recess 11 is a region where the light emitting element 30 isarranged, and as shown in FIGS. 1A and 1B, the pair of lead frames 20are arranged so that respective one ends thereof face with each other atthe bottom of the recess 11 and the light emitting element 30 isarranged on the upper surface of one of the pair of lead frames 20.

As shown in FIGS. 1A to 3, the package 10 has a first side face 12 and asecond side face 13 at a side where the pair of lead frames 20 arearranged. As shown in FIGS. 1A and 1B, the first side face 12 is formedinwardly of a frame side face 21 of the pair of folded lead frames 20.Also, as shown in FIG. 2, the first side face 12 and the second sideface 13 are formed across two side faces of the package 10 where thepair of lead frames 20 are formed. How much the first side face 12 isformed inwardly relative to the frame side face 21 is not limited to anyparticular case, and can be changed as needed depending on how much itis covered by the waterproof resin 2.

As shown in FIGS. 1A and 1B, the second side face 13 is formedcontinuously with the first side face 12 at a lower part thereof, andprotrudes from the first side face 12. Also, as shown in FIGS. 1A and1B, the second side face 13 is protrudingly formed so as to cover theupper part of the lead frame 20, more preferably, so as to cover theupper part of a bent portion 22 of the lead frame 20. Hence, as viewedin a cross-sectional view shown in FIGS. 1A and 1B, the second side face13 is in a shape protruding convexly above the bend portion 22 of thelead frame 20.

As shown in FIG. 1A, when a side face of the light emitting device 1 iscovered by the waterproof resin 2, the waterproof resin 2 repeatsexpansion and shrinkage due to a long-term use, and as shown in FIG. 1B,may be peeled from the first side face 12. However, the light emittingdevice 1 can suppress further peeling of the waterproof resin 2 by astep (indicated by a dashed arrow in FIG. 1B) formed by the first sideface 12 and the second side face 13, thereby preventing moisture likerain water from entering therein.

Also, as shown in FIGS. 1A and 1B, the second side face 13 is formed sothat the protruding side face thereof has a length equal to or longerthan that of the frame side face 21 of the lead frame 20. In thisembodiment, the side face protruding length of the second side face 13is substantially equal to that of the frame side face 21, i.e., as shownin FIGS. 1A and 1B, the second side face 13 and the frame side face 21are flat and form a common plane. Accordingly, as shown in FIG. 1A, thelight emitting device 1 can elongate a distance d₁ from the side face ofthe package 10 to the interior of the light emitting device 1 whichbecomes a moisture entering path when the waterproof resin 2 is peeledmore than a distance d₂ (see FIG. 11A) of a light emitting device 101 ofa related art. Accordingly, since the light emitting device 1 can ensurethe longest moisture entering path at maximum when the waterproof resin2 is peeled, the light emitting device 1 can improve the waterproofperformance. Also, like the light emitting device 101 of the relatedart, when the upper face of the lead frame 120 protrudes from thepackage 110, moisture entering from a space between the waterproof resin2 and the package 110 is likely to enter the interior of the lightemitting device 101 (see FIG. 11B) through the upper face of the leadframe 120. Accordingly, as shown in FIGS. 1A and 1B, by completelycovering the upper face of the lead frame 20 by the package 10, even ifthe peeling of the waterproof resin 2 progresses and reaches the leadframe 20, the light emitting device can be caused to suppress enteringof moisture.

It is not illustrated in the figure but the second side face 13 may beformed so that the side face protruding length thereof is longer thanthat of the frame side face 21 of the lead frame 20. In other words, theframe side face 21 of the lead frame 20 may be arranged inwardly of thesecond side face 13. In this case, also, the light emitting device 1 canelongate a distance from the side face of the package 10 to the interiorof the light emitting device 1 which becomes a moisture entering pathwhen the waterproof resin 2 is peeled more than the distance d₂ (seeFIG. 11A) of the light emitting device 101 of the related art.Accordingly, the light emitting device 1 can ensure the longest moistureentering path at maximum when the waterproof resin 2 is peeled, so thatthe light emitting device 1 can improve the waterproof performance.

When the side face of the light emitting device 1 is covered by thewaterproof resin 2, as shown in FIG. 1A, it is preferable for thewaterproof resin 2 to have an end located within a plane of the firstside face 12. However, the position of the end of the waterproof resin 2is often misaligned in manufacturing. Accordingly, as shown in FIG. 1A,it is preferable that the the package 10 should be formed so that aheight h₁ of the first side face 12 in the thickness direction of thepackage 10 is larger than a height h₂ of the second side face 13 in thethickness direction of the package 10. Accordingly, when the side faceof the light emitting device 1 is covered by the waterproof resin 2 andthe light emitting device 1 is used in an outdoor location, the largerarea of the first side face 12 is ensured than the area of the secondside face 13, and thus application of the waterproof resin 2 becomeseasy so that the end of the waterproof resin 2 is located within a planeof the first side face 12. Since the light emitting device 1 allowsapplication of the waterproof resin 2 with reference to the first sideface 12, the covered level by the waterproof resin 2 can be madeconstant, thereby improving the waterproof performance. Also, since thefirst side face 12 is covered by the waterproof resin 2 in this fashion,the first side face 12 is exposed without being covered by anencapsulation member or a lens member, etc.

The size of the package 10 is not limited to any particular size, andcan be selected accordingly depending on the number of light emittingelements 30 and the purpose and the application. Also, it is preferablethat the material of the package 10 should be an insulative material,and should be also a material which does not easily allow light emittedfrom the light emitting element 30 or external light to passtherethrough and which has a strength to some level. Specific examplesof the material of the package 10 are ceramics (e.g., Al₂O₃, AIN), or aresin, such as a phenol resin, an epoxy resin, a polyimide resin, a BTresin (bismaleimide triazine resin), or a polyphthalamide resin (PPA).

<Lead Frame>

The lead frames 20 are electrodes which electrically connect theelectrical component like the light emitting element 30 with anunillustrated external power source and which apply a voltage to theelectrical component from the external power source. As shown in FIGS.1A to 3, the lead frames 20 include lead frames 20 a and 20 b whichserve as a positive electrode or a negative electrode, respectively.

As shown in FIGS. 1A to 2, the lead frames 20 a and 20 b are each formedof a tabular metal member. As shown in FIGS. 1A to 3, the lead frames 20a and 20 b have respective one ends exposed at the bottom of the recess11 of the package 10, and have respective another ends buried in thepackage 10 so as to protrude to the exterior from the side face of thepackage 10. As shown in FIGS. 1A to 2, the lead frames 20 a and 20 bprotruding to the exterior from the side face of the package 10 are bentalong the side face of the package 10 and the lower face thereof.

As shown in FIGS. 1A and 1B, the light emitting element 30 is arrangedon the upper face of the lead frame 20 a. As shown in FIGS. 1A, 1B and3, the light emitting element 30 arranged on the upper face of the leadframe 20 a is electrically connected to the lead frames 20 a and 20 bthrough wires 50. It is fine if the light emitting element 30 isarranged on the upper face of at least either one of the lead frames 20a and 20 b, and for example, may be arranged on the upper face of thelead frame 20 b or on both upper faces of the lead frames 20 a and 20 b.

Respective sizes of the lead frames 20 a and 20 b are not limited to anyparticular sizes, and can be selected accordingly depending on thenumber of light emitting elements 30 and the purpose and theapplication. An example material of the lead frames 20 a and 20 b is aCu alloy having a surface thereof plated with Au or Ag.

<Light Emitting Element>

The light emitting element 30 is a semiconductor element that emitslight when a voltage is applied. As shown in FIGS. 1A and 1B, the lightemitting element 30 is arranged on the upper face of the lead frame 20a. As shown in FIGS. 1A, 1B, and 3, each light emitting element 30 canbe formed in a rectangular shape. As shown in FIG. 3, three lightemitting elements 30 can be respectively arranged on three lead frames20 a, and respectively emit lights of red (R), green (G), and blue (B).A pixel is configured by mixing respective lights emitted by the threelight emitting elements 30.

It is preferable that the light emitting element 30 should bespecifically a light emitting diode, and such a diode with an arbitrarywavelength can be selected depending on the application. For example,example light emitting elements 30 of blue (light wavelength: 430 nm to490 nm) and green (light wavelength: 490 nm to 570 nm) are ZnSe, anitride-based semiconductor (In_(X)Al_(y)Ga_(1-X-Y)N, 0≦X, 0≦Y, andX+Y<1), GaP, etc. Also, for the light emitting element 30 of red (lightwavelength: 620 nm to 750 nm), GaAlAs, AlInGaP, etc., can be used.

It will be discussed later but when a fluorescent material is introducedin the encapsulation member 40 (see FIGS. 1A, 1B and 2), it ispreferable to use a nitride semiconductor (In_(X)Al_(Y)Ga_(1-X-Y)N, 0≦X,0≦Y, and X+Y<1) that can emit short-wavelength light and which can makesuch fluorescent material excited efficiently. The component compositionof the light emitting element 30, the emitted light color thereof, thesize, and the like are not limited to the above-explained ones, and canbe selected accordingly depending on the purpose.

<Encapsulation Member>

The encapsulation member 40 is for protecting the light emitting element30 and the wires 50 arranged on the lead frames 20 a and 20 b againstdust, moisture, external force, etc. As shown in FIGS. 1A, 1B and 2, theencapsulation member 40 is formed by filling a resin in the interior ofthe recess 11 of the package 10.

A preferable material of the encapsulation resin 40 is a lighttransmissive one which can allow light from the light emitting element30 to pass therethrough, and more specifically, it is preferable to usea silicon resin, an epoxy resin, an urea resin, and the like. Also, inaddition to such materials, a colorant, a light diffusion agent, afiller, a fluorescent material, and the like can be contained.

The encapsulation member 40 can be formed of a single material, or maybe formed as a plurality of layers equal to or greater than two layers.It is appropriate if the filling amount of the encapsulation member 40is such an amount that the light emitting element 30 and the wires 50arranged on the lead frames 20 a and 20 b in the recess 11 of thepackage 10 are just filled.

<Wires>

The wires 50 are conductive wirings that electrically connect theelectrical component like the light emitting element 30 with the leadframes 20. As shown in FIGS. 1A, 1B and 3, the wires 50 electricallyconnect the light emitting element 30 with the lead frames 20 a and 20b.

The diameter of wire 50 is not limited to any particular size, and canbe selected accordingly depending on the purpose and the application.Also, example materials of the wire 50 are a metal, such as Au, Cu, Pt,or Al, and an alloy thereof, but in particular, it is preferable to useAu which is excellent in thermal conductivity.

As shown in FIG. 1A, the light emitting device 1 employing theabove-explained structure is mainly used in an outdoor location and theside face thereof is covered by the waterproof resin 2. As shown in FIG.1B, when the waterproof resin 2 starts peeling due to a long-term use,the waterproof resin 2 is prevented from being peeled up to the boundarybetween the package 10 and the lead frames 20 a and 20 b where moistureis likely to enter by the step formed by the first side face 12 formedinwardly relative to respective frame side faces 21 of the lead frames20 a and 20 b and the second side face 13 protruding so as to coverrespective upper parts of the bent portions 22 of the lead frames 20 aand 20 b, and entering of moisture like rain water can be suppressed,thereby improving the waterproof performance.

When the light emitting device 1 is used in not only an outdoor locationbut also an indoor location, the package side faces of the lightemitting device 1 are covered by the waterproof resin 2 in some cases inorder to improve the waterproof performance, and the same effect can beobtained in this case, too. Also, since the light emitting device 1allows application of the waterproof resin 2 with reference to the sideface 12, the covered level by the waterproof resin 2 can be madeconstant, thereby making the waterproof performance stable.

[Image Display Unit]

Next, an explanation will be given of an image display unit U using theabove-explained light emitting device 1 with reference to FIGS. 4A to5B.

The image display unit U is configured by a plurality of light emittingdevices 1 used for an image display device (display) placed in anoutdoor location. As shown in FIGS. 5A and 5B, the image display unit Uis used for configuring an image display device D. As shown in FIGS. 4Aand 4B, the image display unit U includes the light emitting devices 1,the waterproof resin 2, a circuit board 3, and a frame member 4.

<Light Emitting Device>

As shown in FIGS. 4A and 4B, a plurality of light emitting devices 1 arearranged on the circuit board 3 via a joining member 5 (see FIGS. 6A to6C) to be discussed later. As shown in FIGS. 4A and 4B, the lightemitting devices 1 are arranged in a matrix manner three by three. Thenumber of light emitting devices 1 configuring the image display unit Uis not limited to any particular number, and can be increased ordecreased depending on the purpose. The specific configuration of thelight emitting device 1 is same as one explained above, so that theexplanation thereof will be omitted.

<Waterproof Resin>

The waterproof resin 2 is for preventing moisture, such as rain water inan ambient air or humidity, from entering into the interior of the lightemitting devices 1. The waterproof resin 2 is formed of a silicon resin,and is formed so as to cover the side face of the package 10 of eachlight emitting device 1 on the circuit board 3 and the frame side face21 (see FIG. 1A).

It is preferable that the waterproof resin 2 should be formed so as tocover the frame side face 21 and the second side face 13 and a part ofthe first side face 12 on the circuit board 3 (see FIG. 1A). Morespecifically, the waterproof resin 2 is filled around the light emittingdevice 1 so that the end of the waterproof resin 2 is located within aplane of the first side face 12, i.e., between the upper end of thefirst side face 12 and the bottom end thereof (see FIG. 1A).Accordingly, as shown in FIG. 4B, the image display unit U has thewaterproof resin 2 formed up to a location within a plane of the firstside face 12 of the package 10, so that it can be further surelyprevented that moisture like rain water enters in the interior of thelight emitting device 1. Since the waterproof resin 2 is not filled upto the upper end of the first side face 12, the waterproof resin 2 canbe prevented from going over on the upper face of the light emittingdevice 1, so that reduction of an optical output due to a light emittingface covered by the waterproof resin 2 can be prevented, and as shown inFIGS. 4A and 4B, a space for attaching the frame member 4 can be formed,facilitating the attachment of the frame member 4.

<Circuit Board>

The circuit board 3 is for arranging the plurality of light emittingdevices 1 and for electrically connecting those together andmechanically holding those. As shown in FIGS. 4A and 4B, the circuitboard 3 is formed in a tabular rectangular shape. The circuit board 3is, more specifically, a glass-epoxy resin on which unillustratedconstant-current drive circuit, drive control circuit, communicationcircuit, and the like are mounted. As shown in FIG. 4B, the plurality oflight emitting devices 1 are arranged on the circuit board 3, andrespective side faces of the light emitting devices 1 are covered by thewaterproof resin 2.

<Frame Member>

The frame member 4 is for protecting the circuit board 3 and thewaterproof resin 2 on the circuit board 3. As shown in FIG. 4A and 4B,the frame member 4 is formed in a tabular rectangular shape and has anarea corresponding to that of the circuit board 3. As shown in FIG. 4B,the frame member 4 has a plurality of openings 4 a corresponding to thearea of the plurality of light emitting devices 1. As shown in FIG. 4A,the frame member 4 has the plurality of openings 4 a opposite to theplurality of light emitting devices 1, and is joined with the circuitboard 3 by means of unillustrated screws.

The image display unit U having the above-explained structure includesthe above-explained light emitting devices 1, so that even if thewaterproof resin 2 starts peeling due to a long-term use, the waterproofresin 2 is prevented from being peeled up to the boundary between thepackage 10 and the lead frames 20 a and 20 b where moisture is likely toenter by the step formed by the first side face 12 formed inwardlyrelative to respective frame side faces 21 of the lead frames 20 a and20 b and the second side face 13 protruding so as to cover respectiveupper parts of the bent portions 22 of the lead frames 20 a and 20 b,and entering of moisture like rain water can be suppressed (see FIG.1A), thereby improving the waterproof performance.

When the image display unit U is used in not only an outdoor locationbut also an indoor location, the package side faces of the lightemitting device 1 are covered by the waterproof resin 2 in some cases inorder to improve the waterproof performance, and the same effect can beobtained in this case, too. Also, since the image display unit U allowsapplication of the waterproof resin 2 with reference to the side face12, the covered level by the waterproof resin 2 can be made constant,thereby making the waterproof performance stable.

[Manufacturing Method of Image Display Unit]

Next, a brief explanation will be given of a manufacturing method of theimage display unit U using the light emitting devices 1. Themanufacturing method of the image display unit U includes alight-emitting-device arranging process, a water-proof-resin applyingprocess, and a frame-member attaching process. Respective processes willbe briefly explained with reference to FIGS. 6A to 6C.

<Light-emitting-device Arranging Process>

The light-emitting-device arranging process is for arranging theplurality of light emitting devices 1 on the circuit board 3. In thelight-emitting-device-arranging process, as shown in FIG. 6A, theplurality of light emitting devices 1 are arranged on the circuit board3 at a predetermined interval, and are soldered by respective joiningmembers 5, thereby arranging the light emitting devices 1. The lightemitting devices 1 are arranged in a matrix manner three by three on thecircuit board 3 (see FIGS. 4A and 4B).

<Water-proof-resin Applying Process>

The waterproof-resin applying process is for covering respective sidefaces (surroundings) of the plurality of light emitting devices 1arranged on the circuit board 3 by the waterproof resin 2. As shown inFIG. 6B, in the waterproof-resin applying process, the waterproof resin2 is filled around the plurality of light emitting devices 1 configuringthe image display unit U, and the waterproof resin 2 is formed so as tocover the side faces of the packages 10 of respective light emittingdevices 1 and the frame side faces 21.

<Frame-member Attaching Process>

The frame-member attaching process is for attaching the frame member 4to the circuit board 3 which is covered by the waterproof resin 2 andwhich has the plurality of light emitting devices 1 arranged thereon. Inthe frame-member attaching process, as shown in FIG. 6C, the framemember 4 is attached to the circuit board 3 so that respective lightemitting devices 1 are located at respective openings 4 a eachcorresponding to the size of each light emitting device 1, and isfastened to the circuit board 3 by means of unillustrated screws,thereby forming the image display unit U. At this time, as shown in FIG.6C, attachment is made so that the waterproof resin 2 does not abut therear face of the frame member 4 and is spaced apart therefrom at apredetermined clearance.

[Second Embodiment]

An explanation will be given of a light emitting device 1A according toa second embodiment in detail with reference to FIGS. 7A and 7B. Asshown in FIGS. 7A and 7B, the light emitting device 1A employs the samestructure as that of the light emitting device 1 of the first embodimentother than the shape of a package 10A. Hence, the duplicated structurewith that of the above-explained light emitting device 1 will be denotedby the same reference numeral and the explanation thereof will beomitted.

As shown in FIG. 7A, the light emitting device 1A has the package 10Athat has a groove 14 which is formed between the first side face 12 andthe second side face 13 in the thickness direction of the package 10A ata predetermined depth. The depth and the width of the groove 14 are notlimited to any particular sizes, and can be changed accordinglydepending on the covered level by the waterproof resin 2.

As shown in FIG. 7A, when the light emitting device 1A employing theabove-explained structure is used in an outdoor location and the sideface thereof is covered by the waterproof resin 2, as shown in FIG. 7B,even if there is a possibility that the waterproof resin 2 is peeled dueto a long-term use, the groove 14 formed between the first side face 12and the second side face 13 can prevent the waterproof resin 2 frombeing peeled from the package 10A. Also, even if the waterproof resin 2starts peeling from the side face, the groove 14 can suppress a progressof the peeling of the waterproof resin 2, so that entering of moisturelike rain water can be suppressed, and thus the light emitting device 1Ahas an improved waterproof performance.

[Third Embodiment]

An explanation will be given of a light emitting device 1B according toa third embodiment in detail with reference to FIGS. 8A and 8B. As shownin FIGS. 8A and 8B, the light emitting device 1B employs the samestructure as that of the light emitting device 1 of the first embodimentother than the shape of a package 10B. Hence, the duplicated structurewith that of the above-explained light emitting device 1 will be denotedby the same reference numeral and the explanation thereof will beomitted.

As shown in FIGS. 8A and 8B, the light emitting device 1B has thepackage 10B that includes a third side face 15 formed inwardly relativeto the first side face 12 at the light-emitting-surface side of thelight emitting device 1B from the first side face 12. The light emittingsurface means the surface of the encapsulation resin 40 shown in FIGS.8A and 8B, and the light-emitting-surface side of the light emittingdevice 1B from the first side face 12 means a direction from the firstside face 12 toward the surface of the encapsulation resin 40.

Like the first side face 12, the third side face 15 is formed along twoside faces defined by the pair of lead frames 20 when the package 10B isviewed in a cross-sectional view. How much the third side face 15 isformed inwardly relative to the first side face 12 is not limited to anyparticular level, and can be changed accordingly depending on thecovered level by the waterproof resin 2.

As shown in FIG. 8B, when the light emitting device 1B employing theabove-explained structure is used in an outdoor location and the sideface thereof is covered by the waterproof resin 2, even if thewaterproof resin 2 starts peeling due to a long-term use, a step formedbetween the first side face 12 and the second side face 13 can suppressa progress of the peeling of the waterproof resin 2 from the package10B, and entering of moisture like rain water can be suppressed, therebyimproving the waterproof performance. Also, when the light emittingdevice 1B is used in an outdoor location and the side face thereof iscovered by the waterproof resin 2, the waterproof resin 2 can be appliedwith reference to the third side face 15, so that the covered level bythe waterproof resin 2 can be made constant, thereby making thewaterproof performance stable.

Also, when the amount of encapsulation resin 40 varies at the time ofmanufacturing and the encapsulation resin 40 is leaked out from therecess 11, the light emitting device 1B can suppress the leakage of theencapsulation resin 40 by the step formed between the second side face13 and the third side face 15. Accordingly, the light emitting device 1Bcan prevent the encapsulation resin 40 from sticking to the lead frame20 at the time of manufacturing, thereby suppressing a bonding failurebetween the lead frame 20 and a bonding member like a solder.

At the time of manufacturing, when the amount of encapsulation resin 40varies, the encapsulation resin 40 is leaked out from the recess 11, andthe encapsulation resin 40 sticks to a surface of the package 10B thatis bonded with the waterproof resin 2 (i.e., the second side face 13),the adhesiveness with the waterproof resin 2 may decrease. However, asexplained above, since the leakage of the encapsulation resin 40 issuppressed by the step formed between the second side face 13 and thethird side face 15 in order to prevent the encapsulation resin 40 fromsticking to the surface that is bonded with the waterproof resin 2(i.e., the second side face 13), the reduction of the adhesiveness ofthe light emitting device 1B with the waterproof resin 2 can besuppressed.

[Fourth Embodiment]

A light emitting device 1C according to a fourth embodiment will beexplained in detail with reference to FIGS. 9A and 9B. As shown in FIGS.9A and 9B, the light emitting device 1C employs the same structure asthat of the light emitting device 1B of the third embodiment other thanthe shape of a package 10C. Accordingly, the duplicated structure withthe above-explained light emitting device 1B will be denoted by the samereference numeral and the explanation thereof will be omitted.

As shown in FIGS. 9A and 9B, the light emitting device 1C has thepackage 10C that includes a first inner side face 16 and a second innerside face 17 formed outwardly of the light emitting device 1C relativeto the first inner side face 16. The first inner side face 16 and thesecond inner side face 17 are located inside the recess 11. As shown inFIGS. 9A and 9B, the package 10C has a second groove 18 that is formedbetween the first inner side face 16 and the second inner side face 17in the thickness direction of the package 10C at a predetermined depth.As shown in FIG. 9A, the portion where the second groove 18 is formed isfilled by the encapsulation resin 40. The depth and the width of thesecond groove 18 are not limited to any particular sizes, and can bechanged accordingly depending on the amount of the encapsulation resin40 filled in the second groove 18.

According to the light emitting device 1C employing the above-explainedstructure, the second groove 18 improves the adhesiveness between theencapsulation resin 40 and the package 10C, and thus peeling of theencapsulation resin 40 from the package 10C can be suppressed. Also, asshown in FIG. 9A, when the light emitting device 1C is used in anoutdoor location and the side face thereof is covered by the waterproofresin 2, as shown in FIG. 9B, even if not only the waterproof resin 2but also the encapsulation resin 40 start peeling due to a long-termuse, the second groove 18 formed between the first inner side face 16and the second inner side face 17 can prevent moisture like rain waterfrom entering inside the light emitting device 1C, thereby improving thewaterproof performance.

[Fifth Embodiment]

An explanation will be given of a light emitting device 1D according toa fifth embodiment in detail with reference to FIG. 10. As shown in FIG.10, the light emitting device 1D employs the same structure as that ofthe light emitting device 1 of the first embodiment other thanrespective shapes of a package 10D and lead frames 20A. Hence, the samestructure as that of the above-explained light emitting device 1 will bedenoted by the same reference numeral and the explanation thereof willbe omitted.

As shown in FIG. 10, the light emitting device 1D has the package 10Dformed thicker than that of the light emitting device 1 of the firstembodiment, and has lead frames 20Aa and 20Ab folded in the interior ofthe package 10D. As shown in FIG. 10, the light emitting device 1D has aflat plane where the light emitting element 30 is arranged, i.e., thebottom of the recess 11 provided at a higher location (closer locationto the light emitting surface of the light emitting device 1D) thanexternal bent portions 22 of the package 10D, and has the second sideface 13 provided at a lower location (closer to a mount face of thelight emitting device 1D) than the bottom of the recess 11. Also, asshown in FIG. 10, the waterproof resin 2 is formed so as to cover atleast the second side face 13, and so as not to cover the light emittingsurface (upper face) of the light emitting device 1D.

In order to form the waterproof resin 2 so as not to cover the lightemitting surface of the light emitting device 1D, it is preferable thatthe recess 11 should be formed deeply and the distance between thesecond side face 13 and the light emitting surface should be elongatedas much as possible. However, if the package 10D is in such a shape, thedistance between the light emitting surface of the light emitting device1D and the light emitting element 30 becomes large, and light does noteasily go out due to reflection and optical absorption against the innerwall of the recess 11 of the package 10D.

However, as explained above, the light emitting device 1D has the bottomface of the recess 11 provided at a higher location than the externalbent portions 22 of the package 10D, so that the distance between thelight emitting element 30 and the light emitting surface becomes small.Also, since the second side face 13 is provided at a lower location thanthe bottom face of the recess 11, the distance between the second sideface 13 and the light emitting surface also becomes large. Therefore,according to the light emitting device 1D, both high output andimprovement of yield can be simultaneously accomplished.

It is preferable that a height from the second side face 13 to the lightemitting surface should be a height that enables formation of thewaterproof resin 2 with a good yield, and for example, should be severalmm or so. Also, as shown in FIG. 10, by increasing the height of thefirst side face 12, the light emitting device 1D increases the distancebetween the second side face 13 and the light emitting surface. However,like the light emitting device 1B explained in the third embodiment, athird side face 15 may be further formed.

Although the light emitting devices 1, 1A, 1B, 1C, and 1D and the imagedisplay unit U of the present invention were explained in detail throughthe preferred embodiments, the present invention is not limited to theabove-explained embodiments, and should be interpreted in a broadmeaning based on the appended claims. Various changes and modificationsbased on the above-explained embodiments should be included within thescope and the spirit of the present invention. Respective embodimentsmay be carried out in a combined manner. For example, the light emittingdevice 1 explained in the first embodiment may be combined with thesecond groove 18 explained in the fourth embodiment and shown in FIGS.9A and 9B.

For example, the light emitting devices 1, 1A, 1B, 1C, and 1D employrespective structures having three light emitting elements 30corresponding to R, G, and B in respective recesses 11, but for example,a light emitting element 30 corresponding to any one of R, G, and B maybe arranged and the plurality of light emitting devices 1, 1A, 1B, 1C,and 1D each having such light emitting element 30 may be arrangedproximately to one another in order to form a pixel.

Also, the light emitting devices 1, 1A, 1B, 1C, and 1D employ respectivestructures having the three light emitting elements 30 corresponding toR, G, and B in respective recesses 11, but for example, a protectiveelement like a Zener diode may be further arranged.

What is claimed is:
 1. A surface-mount type light emitting devicecomprising: a package having a recess and a side face comprising a firstside face and a second side face; a pair of lead frames buried in thepackage so that one end of each lead frame is exposed at a bottom of therecess and another end of each lead frame protrudes from the first sideface of the side face of the package; a light emitting element disposedon an exposed portion of at least one of the pair of lead frames; and anencapsulant filling the recess, wherein the package comprises a sideface protruding portion disposed on the side face of the package so asto protrude from the first side face and to completely cover a top of aprotruding portion of the lead frames, the side face protruding portionhaving the second side face of the side face so as to protrude from thefirst side face, wherein a length of the first side face in a directionperpendicular to a bottom face of the package is larger than a length ofthe second side face in the perpendicular direction, and wherein thefirst side face comprises a first face segment above the second sideface in the perpendicular direction and a second face segment below thesecond side face in the perpendicular direction, wherein the first facesegment and the second face segment are coplanar.
 2. The light emittingdevice according to claim 1, wherein the another end of each lead frameis bent to follow the side face of the package and a bottom face of thepackage, and the protruding portion of the lead frames covered by theside face protruding portion corresponds to a lead frame disposed on theside face as part of a bending end of the each lead frame.
 3. The lightemitting device according to claim 1, wherein the package furtherincludes a third side face of the side face of the package disposedinwardly relative to the first side face.
 4. The light emitting deviceaccording to claim 2, wherein the package further includes a third sideface of the side face of the package disposed inwardly relative to thefirst side face.
 5. The light emitting device according to claim 2,wherein a length of the first side face in a direction perpendicular tothe bottom face of the package is larger than a length of the secondside face in the perpendicular direction.
 6. An image display unitcomprising: a circuit board comprising a plurality of the light emittingdevices according to claim 1; and a waterproof resin that is formed soas to cover the side face of the package and the protruding portion ofthe lead frames of each of the plurality of the light emitting deviceson the circuit board.
 7. An image display unit comprising: a circuitboard comprising a plurality of the light emitting devices according toclaim 2; and a waterproof resin that is formed so as to cover the sideface of the package and the protruding portion of the lead frames ofeach of the plurality of the light emitting devices on the circuitboard.
 8. The image display unit according to claim 6, furthercomprising a frame member having a plurality of openings and joined withthe circuit board, the plurality of the light emitting devices beingarranged in the plurality of openings.
 9. The image display unitaccording to claim 7, further comprising a frame member having aplurality of openings and joined with the circuit board, the pluralityof the light emitting devices being arranged in the plurality ofopenings.
 10. The image display unit according to claim 6, wherein thewaterproof resin is formed so as to cover covers the frame side faceprotruding portion of the lead frames, the second side face and part ofthe first side face.
 11. The image display unit according to claim 7,wherein the waterproof resin covers the protruding portion of the leadframes, the second side face and part of the first side face.
 12. Thesurface-mount type light emitting device of claim 1, wherein the secondside face is co-planar with a first lead frame side face and the firstside face is co-planar with a second lead frame side face.
 13. An imagedisplay unit comprising: a circuit board; a plurality of surface-mounttype light emitting devices disposed on the circuit board; and awaterproof resin disposed on the circuit board, wherein each of thelight emitting devices comprises, a package having a recess and a sideface comprising a first side face and a second side face; a pair of leadframes buried in the package so that one end of each lead frame isexposed at a bottom of the recess and another end of each lead frameprotrudes from the first side face of the side face of the package; alight emitting element disposed on an exposed portion of at least one ofthe pair of lead frames; and an encapsulant filling the recess, thewaterproof resin covering the side face of the package and a protrudingportion of the lead frame, wherein the package comprises a side faceprotruding portion disposed on the side face of the package so as toprotrude from the first side face and to completely cover a top of aprotruding portion of the lead frames, the side face protruding portionhaving the second side face of the side face so as to protrude from thefirst side face, wherein a length of the first side face in a directionperpendicular to a bottom face of the package is larger than a length ofthe second side face in the perpendicular direction, and wherein thefirst side face comprises a first face segment above the second sideface in the perpendicular direction and a second face segment below thesecond side face in the perpendicular direction, wherein the first facesegment and the second face segment are coplanar.
 14. The image displayunit according to claim 13, wherein the another end of each lead frameis bent to follow the side face of the package and a bottom face of thepackage, and the protruding portion of the lead frames covered by theside face protruding portion corresponds to a lead frame disposed on theside face as part of a bending end of the each lead frame.
 15. The imagedisplay unit according to claim 13, wherein the waterproof resin coversthe protruding portion of the lead frames, the second side face and partof the first side face.
 16. The image display unit according to claim14, wherein the waterproof covers the protruding portion of the leadframes, the second side face and part of the first side face.
 17. Asurface-mount type light emitting device comprising: a package having atop face, a bottom face and a side face, the side face having astep-like structure comprising a first side face, a second side faceprotruding from the first side face and a connecting face connecting thefirst and second side faces; a lead frame partially embedded in thepackage so that part of the lead frame is disposed outside the packageon the side face, the outside part of the lead frame protruding from thefirst side of the side face, and the protruding step-like structure ofthe side face being adjacent the protruding outside part of the leadframe; a light emitting device disposed in a recess in the packagehaving an opening at the top face of the package so as to be connectedto the lead frame; and a waterproof resin disposed on the side face soas to completely cover the outside part of the lead frame, the secondside face, the connecting face and part of the first side face, whereina length of the first side face in a direction perpendicular to a bottomface of the package is larger than a length of the second side face inthe perpendicular direction, and wherein the first side face comprises afirst face segment above the second side face in the perpendiculardirection and a second face segment below the second side face in theperpendicular direction, wherein the first face segment and the secondface segment are coplanar.
 18. The light emitting device according toclaim 17, wherein a length of the first side face in a directionperpendicular to a bottom face of the package is larger than a length ofthe second side face in the perpendicular direction.
 19. A package for asurface-mount type light emitting device, the package comprising: apackage body having a recess and a side face comprising a first sideface and a second side face; a pair of lead frames buried in the packagebody so that one end of each lead frame is exposed at a bottom of therecess and another end of each lead frame protrudes from the first sideface of the side face of the package body; wherein the package bodycomprises a side face protruding portion disposed on the side face ofthe package body so as to protrude from the first side face and tocompletely cover a top of a protruding portion of the lead frames, theside face protruding portion having the second side face of the sideface so as to protrude from the first side face, and wherein a length ofthe first side face in a direction perpendicular to a bottom face of thepackage body is larger than a length of the second side face in theperpendicular direction, and wherein the first side face comprises afirst face segment above the second side face in the perpendiculardirection and a second face segment below the second side face in theperpendicular direction, wherein the first face segment and the secondface segment are coplanar.
 20. The package of claim 19, wherein the pairof lead frames contain a bend within the package body, wherein the bendis configured to permit each lead frame to protrude from the first sideface at a position below the side face protruding portion.
 21. Asurface-mount type light emitting device comprising: a package having arecess and a side face comprising a first side face and a second sideface; a pair of lead frames buried in the package so that one end ofeach lead frame is exposed at a bottom of the recess and another end ofeach lead frame protrudes from the first side face of the side face ofthe package; a light emitting element disposed on an exposed portion ofat least one of the pair of lead frames; and an encapsulant filling therecess, wherein the package comprises a side face protruding portiondisposed on the side face of the package so as to protrude from thefirst side face and to completely cover a top of a protruding portion ofthe lead frames, the side face protruding portion having the second sideface of the side face so as to protrude from the first side face, andwherein a length of the first side face in a direction perpendicular toa bottom face of the package is larger than a length of the second sideface in the perpendicular direction.
 22. An image display unitcomprising: a circuit board; a plurality of surface-mount type lightemitting devices disposed on the circuit board; and a waterproof resindisposed on the circuit board, wherein each of the light emittingdevices comprises, a package having a recess and a side face comprisinga first side face and a second side face; a pair of lead frames buriedin the package so that one end of each lead frame is exposed at a bottomof the recess and another end of each lead frame protrudes from thefirst side face of the side face of the package; a light emittingelement disposed on an exposed portion of at least one of the pair oflead frames; and an encapsulant filling the recess, the waterproof resincovering the side face of the package and a protruding portion of thelead frame, wherein the package comprises a side face protruding portiondisposed on the side face of the package so as to protrude from thefirst side face and to completely cover a top of a protruding portion ofthe lead frames, the side face protruding portion having the second sideface of the side face so as to protrude from the first side face, andwherein a length of the first side face in a direction perpendicular toa bottom face of the package is larger than a length of the second sideface in the perpendicular direction.
 23. A surface-mount type lightemitting device comprising: a package having a top face, a bottom faceand a side face, the side face having a step-like structure comprising afirst side face, a second side face protruding from the first side faceand a connecting face connecting the first and second side faces; a leadframe partially embedded in the package so that part of the lead frameis disposed outside the package on the side face, the outside part ofthe lead frame protruding from the first side of the side face, and theprotruding step-like structure of the side face being adjacent theprotruding outside part of the lead frame and completely covering a topof the protruding outside part of the lead frame; a light emittingdevice disposed in a recess in the package having an opening at the topface of the package so as to be connected to the lead frame; and awaterproof resin disposed on the side face so as to cover the outsidepart of the lead frame, the second side face, the connecting face andpart of the first side face, wherein a length of the first side face ina direction perpendicular to a bottom face of the package is larger thana length of the second side face in the perpendicular direction.
 24. Apackage for a surface-mount type light emitting device, the packagecomprising: a package body having a recess and a side face comprising afirst side face and a second side face; a pair of lead frames buried inthe package body so that one end of each lead frame is exposed at abottom of the recess and another end of each lead frame protrudes fromthe first side face of the side face of the package body; wherein thepackage body comprises a side face protruding portion disposed on theside face of the package body so as to protrude from the first side faceand to completely cover a top of a protruding portion of the leadframes, the side face protruding portion having the second side face ofthe side face so as to protrude from the first side face, and wherein alength of the first side face in a direction perpendicular to a bottomface of the package body is larger than a length of the second side facein the perpendicular direction.